Ejector sensor fuze

ABSTRACT

A pneumatically operated fuze utilizing the force of the missile ejection position to break the hermetic seal and unlock the arming mechanism. The hermetic seal is a membrane covering the housing in which the fuze is mounted. The locking means are brackets which are straightened by the downward movement of the ejection piston. A bellows is then exposed to the dynamic pressure and expands causing the arming mechanism to arm.

United States atet [Ill 3,631,803

[72] Inventor Edward J. Davis [56] References Cited Riverside, Callf- UNITED STATES PATENTS [21] P 2,989,923 6/1961 Villa et al. 102/81 x [22] 1968 3 048 111 8/1962 Baker et al 102/81 x [451 Patented 1971 3151557 10/1964 Evanoff et 51 102/70 [73] Assignee The United States of America as 3329091 7/1967 An dos 102/70 represented by the Secretary of the Navy g Primary ExaminerBenjamin A. Borchelt Assistant ExaminerC. T. Jordan Attrneys-G. J. Rubens, J. M. St. Amand and T. M. Phillips [54] EJEQTOR SENOR ,FUZE ABSTRACT: A pneumatically operated fuze utilizing the l Drawmg force of the missile ejection position to break the hermetic [52] US. Cl 102/70 R, seal and unlock the arming mechanism. The hermetic seal is a 102/81 membrane covering the housing in which the fuze is mounted. [51] Int. Cl F42c /00, The locking means are brackets which are straightened by the F42c /00, F420 15/28 downward movement of the ejection piston. A bellows is then Field of Search 102/81, 70, exposed to the dynamic pressure and expands causing the B arming mechanism to arm.

SAFE AND LOCKED PATENTEDJAN 41972 3.631; 803

EDWARD J. DAVIS INVENTO'R.

ATTORNEYS EJECTOR SENSOR FUZE The invention herein described may be manufactured and used by or for the Government of the United States of America for govemmenta] purposes without the payment of any royalties thereon or therefore.

The present invention relates to pneumatically operated fuzes and more particularly to pneumatically operated fuze that can be kept hermetically sealed until actual time of launch. In prior known fuzing systems for air launched freefall weapons, sensing of separation and arming of the fuze was accomplished by attaching a lanyard or wire to the fuze and to the launcher so that when the missile was launched the force exerted by the wire was used to arm the fuze. Problems have arisen with high speed aircraft in that the lanyard or wire is whipped by the high-velocity air to cause arming of the weapon prior to launch. In actual practice, attaching the lanyards to different weapons required length adjustments and routing that consume valuable time during racking, especially aboard aircraft carriers.

The present invention provides a fuzing system which senses the separation of the weapon from the launcher and erects a dynamic air pressure probe to sense mass air flow or dynamic pressure for actuating the arming mechanism. Safety and reliability are provided since the fuze is sealed when manufactured and is not opened until the weapon is launched.

Many of the attendant advantages of this invention will become readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

FIG. 1 shows a preferred embodiment of the invention depicting a fuze in a safe and locked condition.

FIG. 2 shows the embodiment of FIG. 1 in a safe and unlocked condition.

FIG. 3 shows the embodiment of FIG. 1 in an armed and unlocked condition.

' Referring now to FIG. 1, there is shown in FIG. 1 a cylindrical housing which is mounted within the missile body 12 by means of a threaded portion 14. The portion of housing 10 projecting beyond the surface of the missile is formed as a T- lug l6 and is used in attaching the missile to a launcher (not shown). Housed with housing 10 is a fuze train consisting of initiator l8, detonator 10, lead 22 and booster 24. Detonator is held by and kept out of line and in a safe position by means of detonator holder 26. Detonator holder 26 is attached to the base 28 of a spring loaded bellows 30. Base 28 is held in the safe position by means of brackets 32. Movement of bellows 30 is permitted only in the downward direction by securing the top cap 29 to mounting lug 39 of housing 10 by soldering or any other suitable means. A chamber 3] positioned within bellows 30 holds a pressure probe 34 which is a spring loaded bellows with an opening 35 which when exposed to the atmosphere can sense air pressure. Pressure probe 34 is held in a compressed condition by means of a membrane 36. Membrane 36 may be a thin disc of aluminum and should provide a hermetic seal between the interior of housing 10 and the atmosphere. A cylindrical member 38 rests on brackets 32 and extends to the inner face of membrane 36. Positioned against the outer face of membrane 36 is the piston 40 of the launcher (not shown). When the weapon carrying the fuze assembly is mounted for launching, piston 40 is held against membrane 36 by means of T-lug 16.

In operation, as shown in FIG. 1, the fuze is in the safe and locked condition. The ejector (not shown) has not been activated and dynamic pressure bellows 30, detonator holder 26 and pressure probe 34 are in a locked position. The fuze is also hennetically sealed by membrane 36. When the weapon ejector (not shown) is fired, piston 40 moves downward and as shown in FIG. 2 has traveled to the end of the stroke but has not been separated from the fuze. Membrane 36 has been pierced and the movement of cylindrical member 38 has straightened brackets 32 freeing dynamic pressure bellows 30. At this time pressure probe 34 has not been permitted to erect because the ejector piston 40 is holding it down. As the weapon falls away from e ector piston 40, pressure probe 34 erects and senses dynamic pressure. This is shown in FIG. 3. The dynamic pressure probe 34 causes air to flow through opening 37 in the base of chamber 31 into bellows causing it to expand. The expanding of bellows 30 forces base 28 and igniter holder downward to align detonator 20 with initiator 18 and lead 22. Initiator holder is locked in position by means of spring 23, ball 25 and detent 27.

I claim:

1. In a pneumatically operated fuze for use in a free-fall weapon, the combination comprising:

a. a hermetically sealed container containing a fuze train and an arming means,

b. said arming means including a pressure probe for sensing dynamic pressure and a bellows coupled to said pressure probe,

c. means associated with said hermetically sealed container for breaking the seal at time of launch of the weapon to permit said bellows to respond to the dynamic pressure sensed by said pressure probe to align said fuze train to an armed condition.

l l k 

1. In a pneumatically operated fuze for use in a free-fall weapon, the combination comprising: a. a hermetically sealed container containing a fuze train and an arming means, b. said arming means including a pressure probe for sensing dynamic pressure and a bellows coupled to said pressure probe, c. means associated with said hermetically sealed container for breaking the seal at time of launch of the weapon to permit said bellows to respond to the dynamic pressure sensed by said pressure probe to align said fuze train to an armed condition. 